"Unlawfully obtained" phone records belonging to West Ham United's vice-chairman, Karren Brady, found their way into the hands of investigators retained by Tottenham Hotspur at the height of their bitter Olympic stadium battle, a high court judge said on Thursday.

At the start of a civil case that could lay bare the depth of the enmity behind the two rival bids for the Olympic Stadium, it was claimed that the accountants retained by Spurs had passed those records to a Sunday newspaper.

The case has been brought by Brady and West Ham to force the accountants PKF and its partner Howard Hill to reveal information. Mr Justice Coulson said it was not disputed by either side that the Vodafone phone records had been "unlawfully obtained by subterfuge".

"At the height of the dispute about the use of the Olympic Stadium Ms Brady's telephone records were unlawfully obtained by subterfuge," said Coulson. "PKF was engaged by Tottenham Hotspur to carry out an investigation that was in some way connected with the Olympic Stadium. PKF have, in the last few days, said they do have copies of the wrongfully obtained telephone records."

PKF and Hill deny being "engaged in any unlawful activity" to obtain the phone records or employing any third parties to do so. Lawyers for Brady claimed that on the eve of the hearing PKF had admitted that Hill and two of his colleagues had passed the mobile phone records to the Sunday Times, which used them as part of the basis for an article in June alleging dirty tricks in the bidding process for the £496m Olympic stadium.

Lawyers for PKF said the firm had at no point employed a third party to obtain the phone records illegally and said they had not been passed to Spurs until the start of the legal proceedings. The club said: "Tottenham Hotspur did not instruct PKF to engage in any unlawful activity and PKF have confirmed that they did not."

It was made clear in court that the proceedings related only to the so-called "blagging" of phone records and not to wider claims of surveillance and phone tapping that have been made by Brady and the Olympic Park Legacy Company and rejected by Spurs and PKF. West Ham's counsel, Ben Jaffey, said that, in a series of letters in July and August, West Ham wrote to Spurs and PKF in an attempt to ascertain whether they were in possession of Brady's phone records. Coulson said the East End club, who will bid again for the Olympic Stadium next month after their original deal fell apart under the weight of legal challenges from Spurs and others, had been given the "traditional runaround" in being passed from one to the other. "It would take a train load of advocates to convince me that Tottenham Hotspur or PKF were in any way co-operative," said Coulson.

Brady and West Ham this year said they were going to court "to obtain full information and documents relating to the unlawful obtaining of Karren Brady's mobile telephone records and to obtain information identifying the wrongdoers responsible for unlawfully obtaining such records".

Coulson rejected an attempt by PKF to have the proceedings heard in private in order to prevent misreporting and avoid unfair slurs on the reputation of Hill and the firm.

He said hearings could be held in private in "wholly exceptional" circumstances and the arguments put forward by PKF came "nowhere near" the necessary test.

The hearing will resume on Wednesday, with Tottenham granted more time to prepare evidence that its lawyers claim will refute allegations made by Brady in her witness statement.

Spurs, who maintained that retaining the running track in the stadium was not commercially viable, have now given up on moving into the Olympic Stadium and this week announced plans to delist from the stock market to boost fund-raising plans for a new ground in Tottenham.